Ashraf M. El Sherbini

Measurement of Electron Density from Stark-Broadened Nanomaterial Plasma

This work communicates results from optical emission spectroscopy following laser14 induced optical breakdown at or near nanomaterial. Selected atomic lines of silver are evaluated for 15 consistent determination of electron density. Comparisons are presented with Balmer series 16 hydrogen results. Of particular interest are measurements free of self-absorption effects. For several 17 silver lines, asymmetries are observed in the recorded line profiles. Electron densities of interest range 18 from 0.5 to 3 × 1017 cm-3, for 5 nanosecond Q-switched Nd:YAG radiation at wavelengths of 1064, 532, 19 and 355 nm, and for selected silver emission lines including 328.0, 338.2, 768.7, and 827.3 nm, and the 20 hydrogen alpha Balmer series line at 656.3 nm. Line asymmetries are presented for the 328.0 nm Ag I 21 line that is measured following generation of the plasma due to multiple photon absorption. This 22 work explores electron density variations for different irradiance levels, and reports spectral line 23 asymmetry of resonance lines for different laser fluence levels. 24